Preparation coping for creating an accurate permanent post to support a final prosthesis and method for creating the same

ABSTRACT

An implant comprising an internal bore having an opening at one end of the implant is initially fixed within a patient&#39;s mouth. A support post on which a final artificial prosthesis will be mounted is attached to the implant by allowing a portion of the post to extend into and attach within the bore of the implant. The post generally extends supragingivally from a base at or beneath the gum surface and contains a retention bulb to assist in registering the axial orientation of an impression cap and the final prosthesis. The impression cap is then placed over the post to assist in taking an impression of the relevant dental region. The impression cap contains means to allow to the retention bulb to snap onto the impression cap. After the impression material is placed to surround the impression cap, post and implant, the impression material and impression cap are removed. A healing cap is placed on the post and acts as a temporary tooth able to last within the patient&#39;s mouth for several months.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.09/761,920, filed Jan. 17, 2001 now U.S. Pat. No. 6,758,672, nowallowed; which is based on U.S. Provisional Application No. 60/176,577,filed Jan. 18, 2000, now abandoned.

FIELD OF INVENTION

The present invention relates generally to a temporary addition to apermanent post in a dental implant system. More particularly, thepresent invention relates to a preparation coping used to accuratelyprep a permanent post that supports the final prosthesis.

BACKGROUND OF THE INVENTION

It has become fairly common to replace a missing tooth with a prosthetictooth attached to a dental implant. The prosthetic tooth preferably hasa size, color and shape that mimics the missing natural tooth, thusrevealing an aesthetically pleasing and structurally sound artificialtooth.

Most current methods by which the prosthetic tooth and implant arecompletely integrated into the patient's mouth require six to ten monthsor longer because two distinct, time consuming steps are involved.First, the implant is inserted into the jawbone and covered by suturingthe overlying gingival tissue. The implant then osseointegrates with thejawbone for a period of about three to six months. Second, the gingivaltissue is reopened and a healing abutment is placed onto the implant.The gingiva is sutured again to allow healing around the implant andhealing abutment. The gingiva must heal for a period of approximatelyfour to six weeks. When the prosthetic tooth is eventually placed ontothe implant, the gingiva easily conforms around the prosthetic tooth andthe overall process is complete.

A single-stage dental implant is typically installed through a ridge inthe jawbone that is covered by gingival tissue. The dental implantprovides an artificial root on which a prosthetic tooth is mounted toreplace a missing tooth that formerly emerged from the jawbone. Thesingle-stage implant comprises an anchoring portion for extending intoand integrating with the jawbone and an integral gingival section thatextends beyond the ridge of the jawbone. Because the gingival section isintegral with the anchoring portion, there is no seam in which bacteriamay collect to cause infections.

Single stage implants, or “transgingival” implants, simultaneouslypromote osseointegration and gingival healing. A lower portion of thetransgingival implant integrates with the jawbone and an upper portionof the implant extends through the overlying gingiva such that thegingiva heals therearound. Thus, the four to six week gingival healingperiod is encompassed in the three to six month osseointegration period.Consequently, the patient is outfitted with a prosthetic tooth in ashorter overall period of time with only one incision into the gingivabeing required, reducing the trauma to that dental region and loweringpatient costs due to the lower total number of dental procedures.

During the preparation of dental restorations supported on implantsembedded in a living jawbone, it is frequently useful to provide apermanent support post connected to the single stage implant. The finalprosthesis fits over the support post. To assist in preparing the finalprosthesis, a post analog is prepped in the laboratory. It is desirablefor the prepped post analog to be identical to the post within thepatient's mouth, however an element for creating these identical piecesand a method for creating such an element does not present exist. Thus,a need exists for a preparation coping to create an accurate permanentsupport post that will support the final prosthesis.

SUMMARY OF THE INVENTION

In accordance with the present invention, an implant comprising aninternal bore having an opening at one end of the implant is initiallyfixed within a patient's mouth. A support post on which a finalartificial prosthesis will be mounted is attached to the implant byallowing a portion of the post to extend into and attach within the boreof the implant. The post generally extends supragingivally from a baseat or beneath the gum surface and contains a retention bulb to assist inregistering the axial orientation of an impression cap and ensuringproper placement of the final prosthesis. The impression cap is placedover the post to assist in taking an impression of the relevant dentalregion. The impression cap possesses means to allow the retention bulbto snap onto the impression cap. After the impression material is placedto surround the impression cap, post and implant, the impressionmaterial and impression cap are removed. A healing cap is placed on thepost and acts as a temporary tooth able to last within the patient'smouth for several months.

A post analog is attached to the impression cap that is seated withinthe impression material. A model can be poured about the post analog,impression cap and impression material to replicate the relevant dentalregion. The plaster model and the post analog are then removed and apreparation coping is installed over the post analog. The preparationcoping assists in properly shaping the post within the mouth.Specifically, the preparation coping and the post analog aresimultaneously prepped to effect the form, orientation and shape of thefinal post. The prepped relief coping is then removed from the postanalog and placed over the post. Once the relief coping has beenprepped, it is essentially a template that is used for preparing thepost in the same manner as the prepped post analog. The prepped postwill then be able to properly and accurately receive the overlying finalprosthesis that was developed from the prepped post analog.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other advantages of the invention will become apparentupon reading the detailed description as follows and upon reference tothe drawings in which:

FIGS. 1 a-1 c are side, insertion end, and gingival end views of animplant according to the present invention;

FIGS. 2 a-2 d are side, section, head end, and insertion end views of acover screw;

FIGS. 3 a-3 c are side, head-end, and insertion-end views of a coverscrew;

FIGS. 4 a-4 d are a side view, supragingival end view, insertion endview, and an assembly view of a post and implant for supporting a dentalprosthesis;

FIG. 5 a is a longitudinal sectional view taken through the middle of animpression cap;

FIG. 5 b is a head-end view of an impression cap;

FIG. 6 is a longitudinal sectional view taken through the middle of ahealing cap;

FIG. 7 is a side view of a post analog;

FIG. 8 is a side view of a preparation coping of the present invention;

FIG. 9 a is a side view of a preparation coping installed on postanalog;

FIG. 9 b is a side view of a prepped preparation coping and prepped postanalog;

FIG. 10 is a side view of the prepped preparation coping of FIG. 9 boverlying the post of FIG. 4 attached to an implant;

FIG. 11 is a side view of a prepped post attached to an implant; and

FIG. 12 is a side view of a post of an alternative embodiment of thepresent invention.

While the present invention is susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and will herein be described in detail. Itshould be understood, however, that it is not intended to limit theinvention of the particular forms disclosed, but on the contrary, theintention is to cover all modifications, equivalents and alternativefalling within the spirit and scope of the invention as defined by theappended claims.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

A preparation coping to assist in developing an accurate permanentsupport post and a method of developing the same has been discovered.Specifically, the preparation coping of the present applicationreplicates the shape and orientation of a prepped post analog andcomprises a modifiable cylinder containing an upwardly tapering innersurface for receiving the upper portion of the support post. The supportpost is tailored by modifying a preparation coping in a mannerreflecting the prepping of the post analog and placing the preparationcoping on the support post and prepping the post in accordance with thepreparation coping.

The dental system of the present invention is designed to create anaccurate support post comprises, in addition to the preparation coping,a post analog and support post, a dental implant, a cover screw, animpression cap and a healing cap. These elements are referred to anddepicted in FIGS. 1-6. Referring specifically now to the figures andinitially to FIG. 1 a, an implant 10 is illustrated having a main body12 with a threaded outer surface 13. The threaded outer surface 13includes a self-tapping region with incremental cutting edges 14 at anapical end 16 of the main body 12. These incremental cutting edges 14are shown in FIG. 1 b and defined in detail in U.S. Pat. No. 5,727,943,entitled “Self-Tapping, Screw-Type Dental Implant”, which is hereinincorporated by reference in its entirety. An axial opening 18 in agingival end 20 of the main body 12 of the implant 10 has three distinctzones proceeding from the uppermost edge of the gingival end 20 into theinterior of the implant 10, a) an inwardly tapering zone 22, b) asubstantially cylindrical zone 24 and c) an internally threaded zone 26.

A cover screw attaches to the implant 10 and is used to protect andenvelop the opening 18 of the implant 10 during osseointegration. FIGS.2 a-2 d illustrate a cover screw 44 that is inserted into the implant10. As shown in side view FIG. 2 a, the cover screw 44 has a head 46, anexternally threaded insertion end 48 and a cylindrical shaft 50 betweenthe head 46 and the insertion end 48.

In use, the insertion end 48 of the cover screw 44, as shown insectional view FIG. 2 b and insertion end view FIG. 2 d, is threadedinto the internally threaded zone to 26 of the opening 18 of the implant10. The cylindrical shaft 50 fits within the cylindrical zone 24 of theopening 18 of the implant 10. The mating of the cylindrical zone 24 andcylindrical shaft 50 provide stability to the combination of the coverscrew 44 and the opening 18. The head 46 has a reentrant under-surface52 that covers the outer surface 28 of the implant 10, as shown in FIG.1 c, when the cover screw 44 is placed on the implant 10. The head 46also has a bore 54, as shown in FIG. 2 c, for engaging a tool, such asan Allen wrench (not shown), that turns the cover screw 44 into theinternally-threaded zone 26 of the implant 10.

FIGS. 3 a-3 c illustrate another cover screw 70 of the presentinvention. Cover screw 70 has a head 72 with a tapering side-surface 74for engaging the tapered zone 22 of the opening 18 of the implant. Thetop surface of the head 72 is designed to be approximately flush withthe uppermost edge of the gingival end 20 of the implants. The taperingsurfaces of the tapered zone 22 and the side-surface 74 are preferablytapered on the same angle suitably to provide a locking taper (e.g.,about 18°) when those surfaces are engaged. As shown in FIG. 3 a, acylindrical shaft 78 is placed between the head 72 and a threadedinsertion end 79, as illustrated in FIG. 3 c. The head 72 has a bore 76,as shown in FIG. 3 b, for engaging a wrench that turns the cover screwinto the internally-threaded zone 26 of the opening 18.

After the implant 10 becomes osseointegrated to the living jawbone, thecover screw 44 or 70 is removed and a post 80, shown in FIGS. 4 a-4 c,possessing a retention bulb 85 is installed and attached to the implant10. It is also possible to attach the post 80 to the implant 10, afterinstallation of the implant, without the use of a cover screw. The post80 includes four zones in a longitudinal sequence, namely, asupragingival zone 82, a locking-taper zone 84, a substantiallycylindrical zone 86, and an externally threaded zone 88. The three zones84, 86 and 88 correspond and mate with the same features, respectively,as the side surface 74, the cylindrical shaft 78 and the insertion end79 of the cover screw 70 of FIG. 3.

In use, the post 80 is attached to the implant 10, as shown in FIG. 4 d,by inserting the externally-threaded zone 88 into theinternally-threaded zone 26 of the opening 18 and rotating the post 80until the tapered zones 84 and 22 engage and lock together. During theprocess of turning the post 80 into the implant, the cylindrical zones24 and 86 provide axial stability to prohibit cross-threading thethreaded surfaces of zones 88 and 26. The axial stability also providesfor true engagement of the tapering surfaces 84 and 22. FIGS. 4 a and 4d also display the supragingival zone 82 having a flat surface 87 thatis useful to prevent a cemented final prosthesis from rotating afterinsertion on the post 80.

To ensure that the tapering surfaces 84 and 22 do not resist inproviding the required axial tension from the engagement of the threadedportions 88 and 26, the tapering surfaces 84 and 22 may be provided witha lubricant to reduce the friction between them. For example, one orboth of the tapering surfaces 84 and 22 may have a gold layer to assistin free rotation.

To take an impression of the relevant dental region within the patient'smouth, an impression cap 90 is installed on the post 80. The impressioncap 90, as shown in FIGS. 5 a-5 b, has generally cylindrically shapedouter side walls, a tapered inner side wall and a flat inner side wall99. The flat inner side wall 99 corresponds to the flat outer side wallof the post 80, as shown in FIG. 4 a, and the post analog 120, as shownin FIG. 8, to prevent rotation of the impression cap 90. The impressioncap 90 has an open bottom 96 bounded by a lowermost rim 98 enclosing anannular shoulder 97. The outer side wall turns inward at the bottomtoward the rim 98. It its top 94, the impression cap 90 has a top wall91 with a contoured hole 92 therethrough. The width of the contouredhole 92 is about the same width as the retention bulb 85 of the post 80that is placed into the hole 92 of the impression cap 90. The retentionbulb 85, disposed on top of the post 80, is designed to fit snuglywithin the hole 92 in the top wall 91 of the impression cap 90. Adentist can easily determine if the retention bulb is correctly seatedby noting the position of the retention bulb. Further, a dentist canimmediately determine if the impression coping has shifted during theimpressioning process. The side walls of the hole 92 contain expansions93 and provide axial retention after the post 80 is inserted through theimpression cap 90 and into the hole 92. Thus, the combination of theretention bulb 85 and the hole 92 register the axial position of theimpression cap 90 on the post 80. The impression cap 90 contains grooves95 to further assist in rotational retention when the impression cap 90is placed within impression material (not shown). The impression cap 90is preferably made of a resilient polymeric material that retains itsshape, such as, for example, Delrin® made by E. I. du Pont de Nemoursand Company of Wilmington, Del.

A head-end view of the impression cap 90 is shown in FIG. 5 b. Afterinsertion of the impression cap 90 onto and over the post 80 so that theimpression cap in 90 grasps the post 80 by at least the retention bulb85, the dentist may, to facilitate insertion of the impression cap 90,prep one or more of the leaves 110 extending from the top surface of theimpression cap 90. The leaves 110 assist in maintain the axial positionof the impression cap 90 within the impression material.

An impression of the dental region assists the dentist to accuratelycreate and construct an artificial tooth. To take an impression,impression material is added to the dental region and allowed to formaround the implant 10, post 80, and impression cap 90. The impressionmaterial is then removed together with the impression cap 90. At thesite where the impression cap 90 was disposed, a healing cap 100, asshown in FIG. 6, is then installed to engage the post 80 that isattached to the implant 10. The healing cap 100, which contains a hole102 through its dome-shaped top 104, is designed to act as a temporarytooth that is cosmetically pleasing and able to last within thepatient's mouth for several months. It is contemplated in accordancewith the present invention that the hole 102 of the healing cap 100 cancontain expansions similar to the expansions 93 of the impression cap90, as shown in FIG. 5 a, to provide axial retention.

A post analog 120 with a retention bulb 122 and a flat surface 124similar to the flat surface 87 of the post 80, as shown in FIG. 7, isthen installed, usually in a laboratory, into the impression materialand attached to the impression cap 90 that is set within the impressionmaterial. The post analog 120 is a device that mimics the external shapeof the upper portion of an implant and post but is designed to beretained in a plaster cast. A model (using, for example, cement) ispoured about the post analog 120, impression cap 90 and impressionmaterial to replicate the dental region surrounding the location thatthe permanent post will be located. The impression material and theimpression cap 90 are then removed to reveal the model of the patient'smouth and the attached post analog 120.

It has been discovered that the use of a preparation coping 150 (seeFIGS. 8 and 9 a) installed on top of the post analog 120 after theimpression material and the impression cap 90 are removed will assist inproperly shaping the post 80 in the mouth. The preparation coping 150 isformed from plastic (e.g. polyoxmethylene), metal or substantially anypolymeric material that allows the clinician to form and shape (i.e.,“prep”) the upper region of the post analog 120 and preparation coping150 simultaneously. The preparation coping 150 and post analog 120permit accurate preparation of the post 80 and provide positiveverification that the post 80 is prepared correctly. It is preferablethat the preparation coping 150 is disposed on the post analog 120during the prepping procedure. However, it is contemplated that the postanalog 120 can be first prepped while the preparation coping 150 is noton the post analog 120. Then, the prepped preparation coping 150 can beattached to the prepped post analog 120 so that the preparation coping150 can be prepped substantially identical to the post analog 120. Aflat internal surface 154 of the preparation coping 150 corresponds tothe external flat surface 124 of the post analog 120 and furtherprovides means to prevent rotation of the preparation coping 150 whiledisposed on the post analog 120 and the post 80.

Specifically, as shown in FIG. 9 a, the plastic preparation coping 150fits over the top of the post analog 120 and closely interfits along anentire length of the post analog 120. The lower rim 152 of the plasticpreparation coping 150 tightly interfits around the edges of the maximumdiameter region of the post analog 120 to secure the plastic preparationcoping 150 to the post analog 120. Alternatively, it is contemplated inaccordance with the present invention that the inner dimensions of thepreparation coping 150 can be the same or slightly less than the postanalog 120. It is also contemplated in accordance with the presentinvention that the preparation coping 150 can grasp onto the rim of thepost analog 120 or the undercut below the major diameter of the postanalog 120.

The compilation of the post analog 120 and plastic preparation coping150 are then prepped to substantially fit within the adjacent naturalteeth in the patient's mouth. As shown in FIG. 9 b, to properly preparethe above-mentioned compilation of components, the post analog 120 andplastic preparation coping 150 are prepped such that the finalprosthesis to be supported by the post 80 is at the proper shape, angle,and displacement to fit within the adjacent teeth in the patient'smouth. After prepping, the laboratory develops the final prosthesis.

The final prosthesis and “prepped” preparation coping 150 are shipped tothe dentist who removes the protective healing cap and places theprepped preparation coping 150 on the post 80 overlying the implant 10within the patient's mouth. The post closely interfits along an entirelength of the post 80. The post 80 will extend through the preppedpreparation coping 150, as shown in FIG. 10. The post 80 willsubsequently be prepped, using the preparation coping 150 as a template,such that the prepped post 80 presents the same shape, angle anddisplacement as the preparation to coping 150. The final implant 10 andprepped overlying post 80 are shown in FIG. 11. It is contemplated inaccordance with the present invention that the top surface of theprepped post 80 is substantially identical to the top surface of thepost analog 120.

Occasionally, the top surface of the post 80 will be prepped such thatthe final prosthesis does not properly align with the top surface of thepost 80. This situation may arise, for example, if the post analog 120is prepped with a flat top surface and the final prosthesis is createdto mimic the flat top surface of the post analog, but the post 80 withinthe patient's mouth is improperly prepped to contain a slight protrudingbump or pimple, the final prosthesis will not seat properly on the post80. To avert this undesirable situation, two preventative measures canbe undertaken. First, the laboratory can prep the top surface of thepost analog to contain a bump or pimple such that the final prosthesiswill contain a depression or dimple. The depression or dimple in thefinal prosthesis created from this post analog will be able to receive apost 80 that is outwardly formed and still allow the final prosthesis toseat properly on top of the post 80. Secondly, the top surface of eachpost 80 can be prepped with a depression or dimple such that a finalprosthesis created with a protruding surface will seat properly on topof the post 80.

In an alternate embodiment, it is contemplated in accordance with thepresent invention that a retention bump 202 exists on a side wall, asshown in FIG. 12, of a post 200 to provide axial retention and preventrotation of any overlying components (e.g., an impression coping 294,preparation coping, or healing cap). It is further contemplated that theretention bump 202 can be located anywhere circumferentially on the post200. Disposing the retention bump 202 on a side wall of the post 200will allow a reduced profile post as compared to the post with theretention bump on the top of the post.

It is contemplated in accordance with the present invention that severalof the components in the dental system described herein can becolor-coded. Specifically, each post, impression cap and post analog canbe coded to indicate the size of each component. For example, a set ofcomponents (i.e., the post, impression cap and post analog) having thesame diameter (e.g., 4 mm) will be coded the same color. Components of adiffering diameter (e.g., 5.5 mm and 7 mm) will be coded differentcolors.

While the present invention has been described with reference to theparticular embodiments illustrated, those skilled in the art willrecognize that many changes and to variations may be made theretowithout departing from the spirit and scope of the present invention.The embodiments and obvious variations thereof are contemplated asfalling within the scope and spirit of the claimed invention, which isset forth in the following claims:

1. An implant-abutment system, comprising: a post adapted to extendsupragingivally, the post having a tapered external surface with a flatportion; and an impression coping including: an uppermost surface havingat least one radially extending flange for being received withinimpression material; a lowermost surface; an internal surface locatedbetween the uppermost and lowermost surfaces and configured to mate withthe external surface of the post of the implant-abutment system, theinternal surface having a tapered surface portion and a flat inner sidewall for engaging the flat portion of the post to hold the impressioncoping non-rotationally on the post; and means for engaging acorrespondingly shaped structure on the post of the implant-abutmentsystem and axially holding the coping on the post, the axial engagementmeans being located such that at least a portion of the tapered surfaceportion is located below the axial engagement means and at least aportion of the tapered surface portion is located above a lower end ofthe axial engagement means, the portion of the tapered surface portionlocated below the axial engagement means being uninterrupted such thatthe lowermost surface is uninterrupted, wherein the at least a portionof the tapered surface portion located above the lower end of the axialengagement means engaging the tapered external surface of the post ofthe implant-abutment system.
 2. The implant-abutment system of claim 1,wherein the at least one flange includes four outwardly extendingflanges.
 3. The implant-abutment system of claim 1, wherein theengagement means is a dimple adapted to receive the correspondinglyshaped structure on the post.
 4. The implant-abutment system of claim 1,wherein the engagement means is a recess adapted to receive a bump onthe post.
 5. The implant-abutment system of claim 1, wherein thelowermost surface includes an annular rim surface for abutting acorresponding annular support surface adjacent the bottom of the post.6. The implant-abutment system of claim 5, wherein the annular rimsurface is angled with respect to a central axis of the implant-abutmentsystem.
 7. The implant-abutment system of claim 1, wherein theimpression coping is made of plastic.
 8. An implant-abutment system,comprising: a supragingivally extending post being a unitarysingle-piece structure and having a top portion, a bottom portion, andan external surface, the external surface having a frustoconicallyshaped tapered wall and a flat wall, the top portion including asubstantially flat top surface, the bottom portion including an angledannular support surface extending circumferentially therearound, and thepost further including a first axial locking member on the externalsurface below the substantially flat top surface; and a plasticimpression coping for engaging the post of the implant-abutment system,the impression coping including an uppermost portion, a lowermostportion, and an internal surface having a tapered wall and a flat wall,the lowermost portion including an angled annular rim for abutting theannular support surface of the post, the internal surface furtherincluding a second axial locking member for engaging the first axiallocking member, the second axial locking member being located on theinternal surface such that at least a portion of the tapered surface islocated above a lower end of the second axial locking member, the atleast a portion of the tapered surface located above the lower end ofthe second axial locking member engages at least a portion of thefrustoconically shaped tapered wall of the post, one of the first andsecond axial locking members creating an undercut that receives acorresponding structure on the other of the first and second axiallocking members.
 9. The system of claim 8, wherein the second axiallocking member is a dimple and the first axial locking member is acorresponding protrusion adapted to mate with the dimple.
 10. The systemof claim 8, wherein the second axial locking member is a recess and thefirst axial locking member includes a bump on the post adapted to matewith the recess.
 11. The system of claim 8, wherein the uppermostportion of the impression coping includes an outwardly extending flange.12. The system of claim 8, further including an implant-abutment analoghaving a supragingivally extending post analog member with a topportion, a bottom portion, and an external surface, the external surfacehaving a tapered wall and a flat wall, the post analog member furtherincluding a third axial locking member on the external surface, thethird axial locking member being substantially similar to the firstaxial locking member and for engaging the second axial locking member ofthe impression coping.
 13. The system of claim 8, wherein theimplant-abutment system includes an implant and an abutment, theabutment fitting within an axially extending bore of the implant andincluding the post.
 14. The system of claim 8, wherein the second axiallocking member is located on the internal surface such that at least aportion of the internal surface is located directly below the secondaxial locking member.
 15. A method for taking an impression of animplant-abutment system having a supragingival post with an externalside surface and a substantially flat top surface, the external sidesurface having a tapered wall and a flat wall, the post furtherincluding an impression coping engagement member along the external sidesurface below the substantially flat top surface, the method comprising:providing an impression coping, the impression coping having anuppermost portion, a lowermost portion, and an internal surface with aflat wall and a tapered wall, the internal surface further including animplant-abutment engagement member for engaging the impression-copingengagement member, the implant-abutment engagement member being locatedon the internal surface such that at least a portion of the tapered wallis located below the implant-abutment engagement member and at least aportion of the tapered wall is located above a lower end of theimplant-abutment engagement member; snapping the impression coping ontothe post of the implant-abutment system such that the impression-copingengagement member locks against the implant-abutment engagement memberalong the external side surface of the post and axially holds theimpression coping on the implant-abutment system; applying impressionmaterial around the impression coping; and removing the impressionmaterial from the implant-abutment system such that the coping isremoved with the impression material.
 16. The method of claim 15,wherein at least one of the implant-abutment engagement member and theimpression-coping engagement member includes an undercut region and theother of the implant-abutment engagement member and theimpression-coping engagement member comprises a corresponding protrudingportion, such that during the snapping the undercut region engages thecorresponding protruding portion.
 17. The method of claim 16, whereinthe impression coping engagement member comprises the undercut regionand the implant-abutment engagement member comprises the correspondingprotruding portion.
 18. The method of claim 17, wherein the undercutregion is included in a bump and the protruding portion protrudes from adimple configured to engage the bump.
 19. The method of claim 15,wherein the implant-abutment engagement member is a dimple and theimpression-coping engagement member is a corresponding protrusionadapted to mate with the dimple.
 20. The method of claim 15, wherein theimplant-abutment engagement member is a contoured hole and theimpression coping engagement member includes a bump on the post, suchthat the snapping includes mating the contoured hole with the bump. 21.The method of claim 15, wherein the lowermost portion of the impressioncoping includes an internal rim surface with an annular shape.
 22. Themethod of claim 21, wherein the post includes an annular shoulder, andthe method further comprises abutting the internal rim surface againstthe annular shoulder.
 23. The method of claim 22, wherein the internalrim surface ring and the annular shoulder are both angled with respectto a central axis of the implant-impression system.
 24. The method ofclaim 15, wherein the uppermost portion includes an outwardly extendingflange.
 25. The method of claim 15, further comprising inserting animplant-abutment analog into the impression coping while the impressioncoping is encased in the impression material.
 26. The method of claim25, wherein the implant-abutment analog includes an impression copingengagement member, and the step of inserting the implant-abutment analogincludes snapping the implant-abutment analog into the impression copingsuch that the impression coping engagement member of theimplant-abutment analog locks against the implant-abutment engagementmember of the impression coping and axially holds the impression copingonto the implant-abutment analog.
 27. The method of claim 15, whereinthe implant-abutment system includes an implant and an abutment, theabutment fitting within an axially extending bore of the implant andincluding the post, the abutment being a unitary, single-piececomponent.
 28. The system of claim 15, wherein the implant-abutmentengagement member is located on the internal surface such that at leasta portion of the internal surface is located directly below theimplant-abutment engagement member.
 29. An implant-abutment system,comprising: an implant for engagement with bone and having an internalbore with a first tapered section; an abutment having animplant-engagement region and a supragingivally extending post region,said implant-engagement region having a second tapered section providinga locking-tapered engagement with said first tapered section of saidimplant, said supragingivally extending post region being a unitarysingle-piece structure and having a top surface, a bottom surface, andan external surface between said top surface and said bottom surface,said external surface having a frustoconically shaped tapered wall and aflat wall, said post region including a first axial locking memberlocated on said external surface and below said top surface such that atleast a portion of said external surface is located below said firstaxial locking member, said first axial locking member having a lowermostend that is located below at least a portion of said tapered wall; and aplastic impression coping fitting over said post region of saidabutment, said impression coping including an uppermost portion, alowermost portion, and an internal surface having a tapered surface anda flat surface, said internal surface further including a second axiallocking member located on said internal surface such that at least aportion of said internal surface is located directly below said secondaxial locking member and at least a portion of said tapered surface islocated above a lower end of said second axial locking member, saidsecond axial locking member engaging said first axial locking member ofsaid post region of said abutment and locking said plastic impressioncoping on said abutment.
 30. The system of claim 29, wherein said firstaxial locking member is a structure extending from said externalsurface.
 31. The system of claim 30, wherein said structure is aretention bump on said external surface and said second axial lockingmember is a dimple for receiving said retention bump.
 32. The system ofclaim 30, wherein said structure is located on said flat surface. 33.The system of claim 29, wherein said first axial locking member islocated on said flat surface.
 34. The system of claim 29, wherein saidflat wall and said flat surface mate to resist relative rotation of saidimpression coping and said abutment.
 35. The system of claim 29, whereinthe uppermost portion of the impression coping includes an outwardlyextending flange.
 36. The system of claim 29, further including animplant-abutment analog having a supragingivally extending post analogmember that is shaped similar to said post region and includes a thirdaxial locking member, the third axial locking member being substantiallysimilar to the first axial locking member and for engaging the secondaxial locking member of the impression coping.